The present invention relates to a device for sampling volatile liquids without emissions of the volatile liquid to be investigated occurring during the sampling. For this purpose, the device has, in addition to the facility for the actual sampling, additional facilities for flushing the sampling device according to the invention with an inert flushing medium, with the used flushing medium and residual quantities of the volatile liquid to be investigated being passed to a disposal system.
For the reasons of work hygiene, environmental protection and safety, especially in chemical or petrochemical plants, it is necessary to sample volatile liquids to be investigated in an emission-free manner. The following requirements, amongst others, are made for a device for emission-free sampling:
1. The sample should be representative of the volatile liquid present at the sampling point. This generally means that the sample, which is to be removed from a container, pipeline or plant part, flows for a certain time, a few minutes for example, before the desired sample is taken in order to prevent liquid remaining in so-called "dead corners" or pipe ends, which are possibly changed, from being transferred to the sample container.
2. Emissions at the sampling point should be avoided so that it is possible to dispense with heavy protective equipment, such as heavy respirators, when dealing with substances which are dangerous in a work environment. Furthermore, contamination of the sample taken should be avoided. Both points require that the sampling device be flushed, and the flushing medium must be disposed of in a suitable fashion.
3. Operating errors with undesirable consequences should be excluded as much as possible.
4. The installation and handling of the sampling device should be possible with acceptable expenditure.
5. The sample bottle should always be filled to the same desired degree, in particular, the sample bottle should have a gas cushion above the volatile liquid to be tested in order to avoid bursting of the sample bottle during temperature variations.